This page lets you control which rules are applied by the selected policy. You can create or modify rules as necessary and you can control the order in which they are applied:
When Enterprise Vault is deciding which files to archive, it applies the archiving rules in the order you list here, beginning at the top. When it finds a rule that applies to a particular file, it applies that rule and then moves on to the next file; it never applies more than one rule to a file.
If there are folder rules defined for a folder, these are applied first. If a file is not matched in the folder rules, the volume rules are applied.
It can be important that you put the rules into the correct order because, when it has found a rule that applies to the file, Enterprise Vault does not search any further.
In this case, *.htm files are never archived because, when Enterprise Vault finds a .htm file, it finds a match according to the first rule. Therefore, it archives the file but does not look at other rules.